Structural properties of PbTe quantum dots revealed by high-energy x-ray diffraction

Abstract

High-energy X-ray diffraction (HE-XRD) experiments combined with an analysisbased on atomic-pair-distribution functions can be an effective tool for probing low-dimensional materials. Here, we show how such an analysis can be used to gain insightinto structural properties of PbTe nanoparticles. We interpret our HE-XRD data using anorthorhombic Pnma phase of PbTe, which is an orthorhombic distortion of the rocksalt phase.Although local crystal geometry can vary substantially with particle size at scales below 10 nm,and for very small nanoparticles the particle size itself influences X-ray diffraction patterns,our study shows that HE-XRD can provide a unique nano-characterization tool for unravelingstructural properties of nanoscale systems.

Keywords: amorphous materials; high-energy x-ray diffraction; quantum dots.